Kinase-Ligand Interaction Fingerprints and Structures database (KLIFS), developed at the Division of Medicinal Chemistry - VU University Amsterdam, is a database that revolves around the protein structure of catalytic kinase domains and the way kinase inhibitors can interact with them. Based on the underlying systematic and consistent protocol all (currently human and mouse) kinase structures and the binding mode of kinase ligands can be directly compared to each other. Moreover, because of the classification of an all-encompassing binding site of 85 residues it is possible to compare the interaction patterns of kinase-inhibitors to each other to, for example, identify crucial interactions determining kinase-inhibitor selectivity.